For example:. However, grinding also increases the overall cost of production. There are several heat treatment services available for gears include surface hardening, tempering, normalizing, annealing, and carburizing. If adequately and properly applied, gear lubricants can help to extend the overall lifespan of a gear by preventing or reducing the amount of stress and fatigue experienced by the gear body and teeth.
However, both the optimal type of lubricant and lubrication method are dependent on the requirements and specifications of the application. Given the employment of the proper lubricant, some of the benefits include the reduction of friction between gear teeth, mitigation of heat generated, and lowering of the amount of noise and vibration produced during operation. Once a suitable lubricant is selected, it must be properly applied. Proper application of a lubricant depends on a variety of factors, including operation speed and load.
The most common application methods for gear lubrication include grease lubrication, splash lubrication, and forced oil circulation lubrication. Beyond the operational and environmental conditions of the application, gears and their designs are also limited by the dimensional specifications—i. For example, gears are typically mated to suit the center distances between machine shafts. However, some applications may require an adjustment of the center distances to better fit within the dimensions of the mechanical gear system or machine, which necessitates a profile shift—i.
Other methods of managing dimensional restrictions include employing gear types and designs that are better suited for limited- or restricted-space applications. For example, internal-external gear pairs allow for the gears and their shaft or base components to be positioned closer together than external-only gear pairs, and hypoid gears allow for components to be placed lower within the machine or system, allowing for more space above.
Gears are used to transfer motion and torque between machine components in mechanical devices. The specification and requirements of the applications—i. In regard to gears, change of direction can refer either to a change in the direction of rotation or a change in the axis of motion.
For example, parallel axes configurations which employ external-only gear pairs allow for a change in the output rotation, but not a change in the axis of rotation. On the other hand, intersecting and non-parallel, non-intersecting axes configurations allow for a change in both the output rotation and the axis of motion. The directional change requirements also influence the optimal type of gear as each type is characterized by a particular configuration e. When mated gears are of different sizes, the resultant output torque and rotational speed are affected as the gear ratio is not equal to i.
Depending on which of the driving and driven gear is the larger and which is the smaller, and consequently which has more teeth and which has less, the resultant gear ratio can produce output speed and torque which are increased or reduced with respect to the input speed and torque. Additionally, as there is an inverse relationship between the two values, either speed can be increased, or torque can be increased, but not both. For torque, the gear ratio represents the ratio of the output torque to the input torque.
Therefore, the output torque can be calculated using the following equation where t represents torque:. Based on the above equation, if the pinion gear is attached to the driven shaft i. On the other hand, if the pinion gear is attached to the driving shaft i. Because torque and speed have an inverse relationship, output speed can be calculated using the following equation where input speed is multiplied by the reciprocal of the gear ratio used in the above torque equation:.
If the pinion gear is attached to the driven shaft i. This result is referred to as gearing up. This result is referred to as gearing down.
There are a wide variety of specifications for gears. But unfortunately, no universal industrial standards exist which define how a gear should be designed and manufactured.
Typically, gears are produced either to the standards set by the individual manufacturer or to suit the design and specifications of a particular machine or system rather than those machines and systems being designed around a standard gear component. The former case makes it more difficult to find the proper gear type and design for an application among the standard components available from gear manufacturers, while the latter case increases the difficulty and cost of finding replacements for the customized part.
While there are no universal gear standards, some countries have implemented their own industrial gear standards, especially in regards to precision gears. When producing a custom gear , the cost of manufacturing is influenced by several factors, including the gear design, construction material, surface treatments and finishes, precision standards, and lubricant and lubrication method.
Industry professional and procurements agents also need to consider the durability and longevity of the custom gear to calculate the optimal maintenance and replacement schedule.
While it is necessary to choose a gear which effectively fulfills the requirements of the application, it is also important to keep in mind the overall lifecycle costs—i. For some applications, a standard, off-the-shelf gear may fulfill the requirements at a much lower cost. Gears are devices used throughout industry for a variety of mechanical machines and systems. Several types of gears are available and employed in a wide range of residential, commercial, and industrial applications, including:.
One of the most widespread manner in which gears are applied is in gearboxes , which are devices comprised of gears contained within an enclosure or housing. These devices utilize a wide range of gear types— including worm gears, bevel gears, helical gears, and spur gears—and are engineered to perform a specific motion or power transmission task within the machine system, from changing the speed and torque to changing output shaft direction.
Similar to most gear systems, gearboxes have a variety of uses, such as in automobiles and other motorized vehicles. Table 2, below, indicates some of the common industries and applications of the types of gears previously mentioned.
Driving Gear : The gear closest to the power source motor or engine and attached to the driving shaft that provides the initial rotational input. Driven Gear : The gear or toothed component attached to the driven shaft which is impacted by the driving gear and exhibits the final output.
Idler Gear : A gear placed between the driving gear and driven gear; typically employed to allow for the transmission of motion without a change in the direction of rotation. Gear Ratio : The ratio between the output value to the input value; typically expressed as the number of teeth of the driven gear output to number of teeth of the driving gear input. Axes Configuration : The orientation of the axes—along which the gear shafts lay and around which the gears rotate—in relation to each other.
Torque : Also referred to as moment or moment of force; the measure of the rotational or twisting force which causes an object to rotate. Efficiency : The percentage value of the ratio of output power i.
This guide provides a basic understanding of gears, the types available, their applications, and considerations for use. For more information on related products, consult Thomas guides and white papers or visit the Thomas Supplier Discovery Platform , where you will find information on over , commercial and industrial suppliers.
Guides Romina Ronquillo Share:. Select From Over , Industrial Suppliers. Receive Daily Industry Updates. Search Over 6 Million Products. Thomas uses cookies to ensure that we give you the best experience on our website. By using this site, you agree to our Privacy Statement and our Terms of Use. Type of Gear. Circular gear body Teeth twisted at an angle around gear body Used for parallel axes configuration Available in right-hand and left-hand designs Available in single and double helical designs Gradual tooth engagement and less impact loading A Quieter, smoother operation A Capable of handling greater loads A Lower efficiency D Higher design complexity, greater cost of manufacturing D Single helical design products thrust force D , double helical does not A.
Pair comprised of a circular gear and a screw-shaped gear Used for non-parallel, non-intersecting axes configuration Large gear ratios and gear reduction A Quiet, smooth operation A Self-locking mechanism A Low transmission efficiency D Large amounts of friction D.
Pair comprised of a gear rack and cylindrical gear Used for parallel axes configuration Rack mated with spur or helical gear Converts rotational motion to linear motion or vice versa Simple design, easy to manufacture A Capable of handling greater loads A Transmission cannot continue infinitely in one direction D Large amount of backlash between mated teeth D Gear teeth experience high friction and stress due to tooth design D.
Bevel Gear — Bevel gears , sometimes just called bevels, are cone shaped gears designed to transmit motion between intersecting axes. They are usually mounted on shafts that are 90 degrees apart, but can be designed for nearly any angle. Another related term you may here is miter gear, which is a type of bevel gear in which the mating pairs have the same number of teeth. Ground Gear — Ground gears are produced by the manufacturing process of gear grinding, also known as gear tooth grinding.
Gear grinding is especially effective when gears distort during the heat treat process and tooth forms no longer meet drawing requirements. Both spur and helical gears can be produced using this method. Helical Gear — While the teeth on spur gears are cut straight and mounted parallel to the axis of the gear, the teeth on helical gears are cut and ground on an angle to the face of the gear.
This allows the teeth to engage mesh more gradually so they operate more smoothly and quietly than spur gears, and can usually carry a higher load. Helical gears are also known as helix gears. Pinion Gear — A pinion is the smaller of two meshed gears in an assembly. Pinions can be either spur or helical type gears, and be either the driving or driven gear, depending on the application.
Pinion gears are used in many different types of gearing systems such as ring and pinion or rack and pinion systems. Pump Gear — A pump gear is the name for a gear used in gear pumps.
They consist of both a driver and driven gear and can be either spur or helical gears. Not to be confused, the term gear pump refers to the entire pump, while pump gears refers to the gears only.
Gear pumps are positive displacement pumps, meaning they pump a constant amount of fluid in each revolution. The volume of fluid in a revolution depends on the geometry of the pump gears i. Learn More. Home Engineering Mechanical Engineering. What is the difference between pinion and gear. Interview Candidate Apr 24th, 14 Mechanical Engineering.
First Prev Next Last. Showing Answers 1 - 14 of 14 Answers. Kassim Zwendebe May 15th, What the different between oring and seal? Pinon is much small than gear. Pinion and Gear. Aman sagar Jan 14th,
0コメント